OF ARTS AND SCIENCES. 113 



The extraeter was of the form recently described by Scheibler,* as 

 tliis was the only one of which we have found a description adapted 

 to the thorough extraction of large quantities of material ; those 

 forms in which the drug is not kept covered with the extracting 

 liquid being apt to leave the edges partially unacted on. The only 

 moililication of Scheibler's apparatus made by us consisted in substi- 

 tuting a cylindrical tin vessel capable of holding 10 kil. of ground 

 turmeric for the smaller glass vessel used by him. With a cooler 

 78 cm. long, the inner tube of which was a flattened U, also made of 

 tin, the thorough extraction of the 10 kil. of turmeric could be accom- 

 plished in little more than a fortnight. The solvent was removed, 

 after it had ceased to act, by forcing out as much as possible of it by 

 air pressure, and then distilling off the rest by filling with steam a 

 jacket which surrounded the vessel containing the turmeric. 



The ligroine extract yielded on evaporation a dark yellow oil, 

 amounting on the average to eleven per cent of the weight of the root. 

 The investigation of this substance will be described in a later paper. 



The ether extract, a reddish-brown mass, varying in consistency 

 from semi-liquid to solid according to the period of the extraction at 

 which it was obtained, was treated with successive small quantities of 

 cold alcohol, which dissolved the viscous impurities more easily than 

 the curcumin. In very obstinate cases washing with ether was found 

 advantageous ; if, on the other hand, the extract was comparatively 

 free from resin, it could be washed with alcohol upon a filter. In either 

 case the residue was purified by reciystallization from alcohol until ,it 

 showed the constant melting-point 178°. 



The average yield of curcumin was 0.3 of one per cent : this, how- 

 ever, is only the amount that can be extracted by the process just 

 described; the quantity contained in the root is much larger, as a con- 

 siderable amount remained mixed with the resinous impurities, 

 and the green fluorescence of the crude turmeric oil pointed to the 

 presence of some curcumin in this substance. 



Composition of Curcumin. 



The following comi)ustions were made of the curcumin purified as 

 just described and dried at 100^. In most of these analyses a slight 

 ash was left, the amount of which has been subtracted from the weight 

 of substance before calculating the percentages. 



* Ber. d. ch. G. 1880, p. 338. 



VOL. XVII. (n. S. IX.) 8 



